See attached image
The Attempt at a Solution
I know that since the problem gives centimeters, there are initial changes to units to be made in the permittivity constant.
This makes it 8.86x10^-9 N/nanoCoulombs and 100 mm.
But I'm not sure how to apply my electric field equation.
Since it is an equilateral triangle, the two positive charges on either side are the same, so that value is doubled. The angles are 30°. I'm not sure what to do beyond this. Is this a case of the y-values canceling, and then integrating the x-values?
Please help. Thanks in advance!